Inhypoplasticleftheartsyndrome(HLHS),Theheart Sleftside

Note:beforereadingthespecificdefectinformationandtheimage(s)thatareassociatedwiththem,itwillbehelpfultoreviewnormalheartfunction.

Whatisit?

Inhypoplasticleftheartsyndrome(HLHS),theheart’sleftside—includingtheaorta,aorticvalve,leftventricleandmitralvalve—isunderdeveloped.

Whatcausesit?

Inmostchildren,thecauseisn’tknown.Somechildrencanhave

otherheartdefectsalongwithHLHS.

Howdoesitaffecttheheart?

InHLHS,bloodreturningfromthelungsmustflowthroughanopeninginthewallbetweentheatria(atrialseptaldefect).Therightventriclepumpsthebloodintothepulmonaryarteryandbloodreachestheaortathroughapatentductusarteriosus(seediagram).

Howdoesthedefectaffectmychild?

Thebabyoftenseemsnormalatbirthbutcomestomedicalattentionwithinafewdaysofbirthastheductuscloses.Thebabymayappearashen,haverapidanddifficultbreathingandhavedifficultyfeeding.Thisheartdefectisusuallyfatalwithinthefirstdaysormonthoflifeunlessit’streated.

Whatcanbedoneaboutthedefect?

Thisdefectisn’tcorrectable,butsomebabiescanbetreatedwithaseriesofoperations,orhearttransplantation.Untilanoperationisperformed,theductusiskeptopenbyintravenousmedication.Becausetheseoperationsarecomplexandneedtobeadaptedforeachchild,it’snecessarytodiscussallthemedicalandsurgicaloptionswithyourchild’sdoctor.

Ifyouandyourchild’sdoctoragreethatsurgeryshouldbeperformed,itwillbedoneinseveralstages.Thefirststage,referredtoastheNorwoodprocedure,allowstherightventricletopumpbloodtoboththelungsandthebodywithouttheneedfortheductustobekeptopen.BloodisdirectedtothelungsthrougheitheraBlalock-Taussig(arrowoninsertedpicture)orSanoshunt.TheNorwoodproceduremustbeperformedsoonafterbirth.

Thesecondstage(bidirectionalGlennorhemi-Fontan)isusuallyperformedbetween4and

12monthsandthethirdstage(lateraltunnelFontanorextracardiacFontan)isusuallyperformedbetween18monthsand3years.

Theseoperationscreateaconnectionbetweentheveinsreturninglow-oxygen(bluish)

bloodtotheheartandthepulmonaryartery.Thegoalistoallowtherightventricletopumponlyoxygenatedbloodtothebodyandtopreventorreducecyanosis(lowerthannormalbloodoxygenlevels).Someinfantsrequireseveralintermediateoperationstoachievethis.

SomedoctorsrecommendhearttransplantationtotreatHLHS.Althoughitcanprovidetheinfantwithaheartthathasnormalstructure,theinfantwillrequirelife-longmedicationstopreventrejection.Manyothertransplant-relatedproblemscandevelop,andtheseshouldbediscussedwithyourchild’sdoctor.

Whatactivitiescanmychilddo?

ChildrenwithHLHSmaybeadvisedtolimittheirphysicalactivitiestotheirownendurance.Generally,manycompetitivesportsposegreaterrisk.Yourchild’spediatriccardiologistwillhelpdeterminetheproperlevelofactivity.

Whatwillmychildneedinthefuture?

ChildrenwithHLHSrequirelifelongfollow-upbyacardiologistforrepeatedchecksofhowtheirheartisworking.VirtuallyallchildrenwithHLHSwillrequireheartmedicines,heartcatheterizationandadditionalsurgery.

Whataboutpreventingendocarditis?

ChildrenwithHLHSareatincreasedriskfordevelopingendocarditis. Askyourpediatriccardiologistaboutyourchild’sneedtotakeantibioticsbeforecertaindentalprocedurestohelppreventendocarditis. Seethesectiononendocarditisformoreinformation.